Cellular Respiration

State the three common features of all the respiratory organs like skin, gills and lungs.

Fill in the following blank with suitable word:

The actual exchange of gases takes place in the ___________ of the lungs.

It has been found that people living in very high mountains have many more red corpuscles in their blood than people living in plains. Which one of the following best accounts for this phenomenon?

Which of the following is an incorrect statement?

Given below is an example of certain structure and its special functional activity:

"Kidney and excretion".

Fill in the blanks on a similar pattern.

Mitochondria and _____________.

Name the body structure concerned with the given functional activity:

Provides actual diffusion of respiratory gases in the lungs.

Name the type of respiration in which the end product is:

C₂H₅OH and CO₂

Give one example  where such a respiration can occur.

Some sugar solution is taken in a test-tube and a little of substance X in powder form is added to it. The mouth of test-tube is closed with a cork and allowed to stand for sometime. On opening the cork, a characteristic smell of substance Y is obtained and a gas Z is also observed to be formed. The gas Z extinguishes a burning matchstick.

(a) What could be (i) X, (ii) Y, and (iii) Z?

(b) What is the process of converting sugar into substance Y by the action of X known as?

(c) What type of respiration is exhibited by X in the above process?